Reaching a maximum length of 7m, the Greenland shark (Somniosus microcephalus)is a fish of extremes. Not only is it big, but it’s also deep – very deep
Brown, black or dark grey in colour, with a caudal fin and two small dorsal fins
Grows to maximum length of 7m
Found throughout the northern Atlantic and the Arctic
Need to know
Reaching a maximum length of 7m, the Greenland shark is a fish of extremes. Not only is it big, but it’s also deep – very deep. During the summer months it averages a depth of around 500m and has even been recorded in water as deep as 1,000m. However, come the winter and the Greenland heads for the surface, cruising the edges of icebergs and glaciers.
It’s not an easy life for this elusive but slow-moving shark, which has been described as ‘an overgrown dogfish’. Not only does it have to contend with fast-moving prey, it is also the victim of a particularly voracious parasite, the copepod Ommatokoita elongata. These parasites attach themselves to the corneas of Greenland sharks, rendering them almost blind. It was thought by some scientists that the copepods could be aiding Greenland sharks by attracting prey. However, this theory has taken something of a bashing from US shark parasitologist George Benz’s findings that this particular copepod is not bioluminescent. Whatever the case, in the dark world of the deep, the Greenland has little use for sight and can rely far better on its excellent sense of smell. Perhaps that accounts for the shark’s varied diet, a case of ‘bite now, questions later’. Contents found in the stomach of Greenland sharks include a variety of fish, shellfish, seals, porpoises and even reindeer!
If it isn’t enough that the Greenland shark is blind, slow-moving and has indiscriminate dietary habits, it also smells strongly of ammonia. Eskimo mythology tells the story of a woman who washed her hair with urine and was towelling it dry, when the wind blew the cloth into the sea and it was turned into the Greenland shark.
Another fact worth knowing – especially if you’re considering making an expedition to the Arctic – is that the flesh of the Greenland shark is poisonous. If you’re still keen on eating it then it must be boiled and dried several times to rid it of the poison, but on balance I think you’d be better off packing a tin of Spam.